package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.*;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;

    @Resource
    private IFollowService followService;

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryBlogById(Long id) {
        //1.查询blog
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("博客不存在");
        }
        //2.查询blog有关的用户
        queryBlogUser(blog);
        //3.查询当前用户是否点赞
        isBlogLiked(blog);
        return Result.ok(blog);
    }



    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog ->{
            this.queryBlogUser(blog);
            this.isBlogLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        //1获取当前用户id
        Long userId = UserHolder.getUser().getId();
        //2判断用户是否点赞
        Double score = stringRedisTemplate.opsForZSet().score(BLOG_LIKED_KEY + id, userId.toString());
        if (score == null){
            //3如果未点赞，可以点赞
            //3.1数据库点赞+1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            if (BooleanUtil.isTrue(isSuccess)){
                //3.2redis保存用户点赞记录
                stringRedisTemplate.opsForZSet().add(BLOG_LIKED_KEY + id, userId.toString(),System.currentTimeMillis());
            }
        }else {
            //4如果已点赞，取消点赞
            //4.1数据库点赞-1
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            if (BooleanUtil.isTrue(isSuccess)){
                //4.2redis删除用户点赞记录
                stringRedisTemplate.opsForZSet().remove(BLOG_LIKED_KEY + id, userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        //查询top5的点赞用户
        String key = "blog:liked:" + id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if (top5 == null || top5.isEmpty()){
            return Result.ok();
        }
        //解析出用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        List<UserDTO> userDTOS = userService.query().in("id", ids).last("order by field (id,+"+idStr+") ")
                .list()
                .stream().map(
                user -> BeanUtil.copyProperties(user, UserDTO.class)
        ).collect(Collectors.toList());

        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //保存探店博文
        boolean isSuccess = save(blog);
        if (!isSuccess){
            return Result.fail("新增笔记失败");
        }
        //查询笔记作者的id
        Long blogUserId = blog.getUserId();
        //推送id给所有粉丝
        List<Follow> list = followService.lambdaQuery().eq(Follow::getFollowUserId, blogUserId).list();
        list.forEach(follow -> {
            //获取粉丝id
            Long userId = follow.getUserId();
            stringRedisTemplate.opsForZSet().add(FEED_KEY + userId, blog.getId().toString(), System.currentTimeMillis());
        });
        //返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //获取当前用户
        Long userId = UserHolder.getUser().getId();
        //查询收件箱
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet().reverseRangeByScoreWithScores(FEED_KEY + userId, 0, max, offset, 2);
        //非空判断
        if (typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //解析数据:blogId，mintime，offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for (ZSetOperations.TypedTuple<String> typedTuple : typedTuples) {
            //获取id
            String idStr = typedTuple.getValue();
            ids.add(Long.valueOf(idStr));
            long time = typedTuple.getScore().longValue();
            //获取分数
            if (time == minTime){
                os++;
            } else{
                minTime = time;
                os = 1;
            }

        }
        //根据id查询blog
        String idStr = StrUtil.join(",",ids);
        List<Blog> blogs = query().in("id", ids).last("order by field (id,+"+idStr+") ")
                .list();
        blogs.forEach(blog ->{
            //查询blog有关的用户
            queryBlogUser(blog);
            //查询blog是否被点赞
            isBlogLiked(blog);
        });
        //返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);
        return Result.ok(r);
    }


    private void isBlogLiked(Blog blog) {
        UserDTO user = UserHolder.getUser();
        if (user == null){
            return;
        }
        Long userId = UserHolder.getUser().getId();
        //2判断用户是否点赞
        Double score = stringRedisTemplate.opsForZSet().score(BLOG_LIKED_KEY + blog.getId(), userId.toString());
        blog.setIsLike(score != null);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}
